[Kenwood] Kenwood Battery Pack Repair (BP-38/39)

[Roy Morgan]

At 07:57 AM 9/10/02 -0500, "Linden, Mike (BRC-Hes)" wrote:
>   Has anyone successfully opened-up the BP-38/39 battery packs and replaced
>the batteries? If so, how? My TH-G71A's BP-38 and BP-39 packs have acquired
>a few shorted cells and I'd prefer to fix them myself


Michael,

These nickel cadmium rechargeable cells, I assume.  If so, you  may be able 
to UN-short them.

Note: Un-shorting a nicad cell may work for a while only to have it fail 
again later, but it's worth a try.

Here is what to do:
Test your cells to be sure which ones are shorted.
Go out to your car and find the battery.  Bring with you a stout clip lead 
or two. You will do a bit of damage to the end of the cell and the clip 
lead most likely, so use non-fancy ones.  Connect one end of the shorted 
cell to the same polarity post on the battery.  Clip the stout clip lead 
onto the other terminal of the battery and then:

BRIEFLY apply the free end of the clip lead to the other end of the cell 
very fast.. just for a moment.. you'll get a spark (unless the cell is 
open).   If you do it a second time and the spark is less, you may have had 
a success.

  Now measure the voltage of the cell.. if it is not zero, you have cleared 
the short and can put the cell back into re-charge.  Do not be tempted to 
"recharge" the cell from the 12 volt car battery.

Some shorts are so severe that they do not open up.  Do mot make continuous 
connections.. only VERY BRIEF contact.

You should access the actual end terminal of the cell ... some disassembly 
may be required.  If all this fails, there are a couple or more vendors who 
sell sets of cells for battery pack replacement.. "The Battery Man" is one.

The Law of Inverse Perversity states that if you purchase spare sets of 
cells before your original battery pack fails, the original one will last 
for years more and you'll wonder why you did it.  If you do not have any 
spare, the original set will fail JUST before a field day or other 
important event.

Roy
Author of the Law of Inverse Perversity,
and who just ran into his spare set, now about 4 years old and never used.



- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
7130 Panorama Drive, Derwood MD 20855
Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
roy.morgan@nist.gov --